## jagr2713 one year ago m=0 through (-9,1)

1. jagr2713

Graph the line

2. Nnesha

m= slope so first write the equation y=mx+b where m is slope and b is y-intercept substitute x and y for (-9,1) point

3. Nnesha

remember x =something you would draw vertical line (undefined slope when slope is zero you would draw horizontal line

4. anonymous

if the slope is 0 that means that $$y_2 = y_1$$ so that $$y_2-y_1 = 0$$ and that only occurrs on a horizontal line

5. jagr2713

So i know when its 0 its undefined and undefined is vertical line so i just graph it??

6. Nnesha

when the slope is zero it wouldn't be undefined

7. Nnesha

vertical line = undefined slope horizontal line = (slope =0)

8. jagr2713

ok so how do i graph this question

9. Nnesha

$\huge\rm \color{reD}{y} = m\color{red}{x}+b$ replace m with 0 and (x,y) with the point (-9, 1) solve for b

10. anonymous

$$slope = {\color{green}{ m}}= \cfrac{rise}{run} \implies \cfrac{{\color{blue}{ y_2}}-{\color{blue}{ y_1}}}{{\color{red}{ x_2}}-{\color{red}{ x_1}}}\implies \cfrac{0}{something}\implies 0\impliedby defined \\ \quad \\ \begin{array}{ccllll} x&y \\\hline\\ -9&1\\ -1000&1\\ +1000&1\\ \pm \infty&1 \end{array}\qquad y=1\impliedby \textit{horizontal line}$$

11. jagr2713

so infinity 1? i dont get the points D:

12. Nnesha

$\rm \frac{ someting }{0 }=undefined$

13. Nnesha

points ? what do you mean ? srry

14. jagr2713

i have to graph it and to graph u need at least 2 points

15. Nnesha

you can write an equation with one point and slope $\huge\rm \color{reD}{y} = m\color{blue}{x}+b$ $\huge\rm (\color{blue}{x},\color{reD}{y})=(\color{blue}{-9},\color{red}{1})$

16. Nnesha

substitute y for 1 and x for -9 m=0 $\huge\rm \color{reD}{1}=-9(\color{blue}{0})+b$ (b is y-intercept) solve for b

17. jagr2713

1

18. Nnesha

yes right so now we should plugthem into the original equation of slope intercept form $\huge\rm y=0x+1$ 0 times x= 0 so you have left with y =1 that's what you should graph

19. Nnesha

|dw:1440721541175:dw| this one is pretty simple slope is 0 just draw a horizontal line where y =1

20. jagr2713

|dw:1440721702698:dw|

21. Nnesha

ye looks good

22. Nnesha

and if the equation is $\huge\rm y=3x+2$ to graph this equation you should always start with the y-intercept y-intercept is a point where line intersect y-axis

23. Nnesha

|dw:1440721805900:dw| y-intercept = 2 so draw a point where y =2

24. Nnesha

|dw:1440722012910:dw| $\rm slope =\frac{ rise }{ run }$ in this equation slope =3/1 $\huge\rm \frac{ rise }{ run }=\frac{ 3 }{ 1 }$ rise =3 run=1 so i'll go 3 units up from 2 and then one unit to the left side

25. Nnesha

any question ?

26. jagr2713

I got it correct thanks :D

27. Nnesha

np